Improvement in mill-picks



J. CUMMINGS.

Mill-Picks.

Patented June 24,1873.

Wrze s s es:

AM FHoTo-UTHoG/PAPH/c on. Mw'osgamve Plenum) JOTHAM CUMMINGS, OF WESTCHARLESTON, VERMONT.

IMPROVEMENT IN MILL-PICKS.

Specification forming part of Letters Patent No. ldhlil, (lated June24,1873; application filed April 24, 1873.

To all whom t may concern:

Be it known that I, JorHAM CUMMnvGs, of West Charleston, Orleans county,Vermont, have invented certain Improvements in Mill- Picks, of which thefollowing is a specification:

This improvement is based upon a class of mill-picks shown and describedin Letters- Patent of' the United States issued to me on the 11th day ofJuly, 1871, and relates mainly to such a construction ofthe pick as willenable me to relieve the strain upon the pickbladcs, and lessenliability of breakage of the same; and also to obtain greater strengthin the head of the picks without increasing its weight, and enable it todeliver a more effective and well-directed blow than heretofore.

The nature of the pick embodied in my Letters Patent above namedconsists in the employment of a flat bar, having an enlargedwedge-shaped head at one end to retain itselfl in place within thepick-head or stock, and a toothed rack upon one side, into one of therecesses of which the sloping end ofthe blade enters, the rack havingthe effect of preventing the blade" from being driven into the head bythe force of the blow upon a stone, while the wedge in its turn servesto clamp the blade firmly between it and the socket in the head in whichit is situated. In this patented pick the lower portion of the socket orchannel ofthe stock7 receives the whole force of the blow, and as thewedge which secures the blade in place exerts a powerful expanding forcethereupon, I ain compelled to provide a very heavyr stock, the excess ofits weight being at the lower end, which tends to overbalance it, andrender the handle liable to turn in the hand.

The nature of my present improvement consists in dividing the pick-headinto two parts, one stationary, and bearing the handle, and the otherdetachable, and formed upon its inner face with a series of teeth toengage the blade and prevent its'being driven upward into the head, thedetachable plate having a loop which embraces the lower wedge-shapedtermination of the stationary block, while the upper part of the formeris provided with wedge-shaped lips, which enter correspondingly-shapednotches in the stationary head or block, the said parts being soarranged that a blow upon the sharp end of the blade tends to settle theparts together, and Iirmly clamp the blade between the two.

In the drawing accompanying this specification, Figure l is a sideelevation; Fig. 2, a vertical and longitudinal section; and Fig. 5, ahorizontal section of a mill-pick embodying iny improvements. Fig. 4 isa front face view of the pick, while Fig. 5 is a vertical section of thestock.

In these drawings, the head or stock ofthe pick is shown as composed oftwo parts, one ot' which, A, is stationary, and bears the handle B, andthe other, C, is detachable, and

constitutes, in connection with the base A, a

clamp to secure the blades firmly in place. The base A is substantiallyan oblong block of metal, having a convex rib, D, upon its rear side fora portion of its length, to impart the greatest strength at the centerof the handle or thereabout, and formed upon its front face and at theupper part thereof, with sideledges or walls a a to retain the clamp Gin place against lateral displacement while adjusting the blade, and atits extreme upper part with tapering or Haring channels b b formed inears c c making part of the block, as shown in Fig. 5 ofthe drawings,the lower rear side A of the head-or block being a tapering wedge. Thedetachable or removable portion G of the stock is also a metal plate, ofa size and form substantially similar to the base or head A, and, likeit, is considerable thicker in its center than at its ends. Thisclampplate C bears at its lower end a clasp or loop, E, which envelopsthe lower and corresponding post or wedge A of the head, while theextreme upper end of the said plate C is formed upon each side with awedge-shaped lip, 7c, as shown in Fig. 6 ofthe drawings, which is a sideview of the plate G, these vlips entering the tapering channels ornotches b b of the head A, and serving, in connection with the wedge Aand loop E, to force the clamp-plate with great power toward the head,and against its front race, or a spring, F, let into such face, as shownin Fig. 2 of the drawings. rlhe inner face of the clamp-plate C isconverted into a range of sloping or ratchet teeth, e e, &c. with whichteeth the blade G engages, this blade being a thin plate of steel, of awidth about equal to that of the head A, and sloping at one end at anobtuse angle, as shown at f, to correspond with the slope of the teethc.

In using this pick, the clamp-plate C and pick-blade G are placed faceto face with the sloping end f of the latter engaging one of the teethof the former, and both applied to the head A, as shown in thedrawings--thatis, with the clasp E inclosing or embracing the wedge A',and the lips 7c k entering the channels b b.

It will be seen that a blow upon the cuttin g end of the blade willdrive the latter and the clamp-bar upward andenibrace the head A withgreat power, the result of this construction of a pick being that themore powerful the blows ot the implement upon a stone the more iirmlywill the blade be coniined in place, while upon reversing the head ofthe implement end for end, and striking the opposite or upper end of theclampbar upon any solid object with a quick blow, both clampplate audblade will be released, and can at be once detached.

Owing to the frequency with which the blades of the pick, when in use,must be removed for sharpening, the facility which this constructionenables this removal to be eii'ected, adds great value to theseimplements.

As the blade wears, it is to be lowered, step by step, from one tooth toanother ot' the clamp-plate, and my construction of parts enl ables meto securely hold a blade in place until nearly worn out.

The form of the head A and clamp-plate C, being thickest in the centeror thereabout, together with the employment of the loop E and notches bb, provides great strength, and enables me to make the pick-head of anydesirable length7 while at the same time its weight is reduced ascompared with previous productions. The form of the head and plate alsoprovides a perfectly balanced implement, and enables a blow to bedirected to the best advantage.

It is obvious that the wedges or lips 7c 7i: mayllbe formed upon thehead-bloclr A, and the ears c c upon the clamp-plate.

I claim- 1. A mill-pick head consistingI of the stationary part A andmovable part C constructed and fitted together to hold the blade betweenthem, substantially as described, the one being provided with the lipsI), and the other with. loop E, arranged and operating to clamp the twofirmly together as set forth.

2. The combination of the head A and plate O with an interposed blade,the head being formed with the daring channels or notches b b and wedgeA', and the plate with the lips k k, loop E, and teeth e e, 52o.,substantially as and for purposes stated.

lVitnesses: JOTHAM CUMMINGS.

` CHARLEs CARPENTER,

HENRY CAMPBELL.

